1. Field of the Invention
The present invention generally relates to the power management of physical layer devices (PHYs). More specifically, the present invention provides the reliable operation of a PHY at a reduced power level.
2. Background Art
Various standards exist which define signaling characteristics and performance requirements to insure interoperability between PHYs from different vendors. PHYs are designed to fully comply with all aspects of a standard to be considered “standard compliant.” For example, IEEE 802.3 specifies that a 10 Gbps PHY must be capable of reliable operation over 100 meters of cable.
A primary market for 10 Gbps PHYs is in data center applications where the majority of cables are often less than 45 meters. PHY complexity and power dissipation are directly proportional to the maximum length of cable it must drive. To be standard compliant, the complexity and power necessary for 100 m operation is required even if the PHY is connected to cables significantly shorter than 100 m. This requirement causes a PHY to consume more power than necessary to provide reliable communication and operation over cable lengths that are less than 100 m. Further, multiple instances of a 10 Gbps 100 m-capable PHY can exceed the power budget of many applications due to this requirement.